Generally, there are three techniques which have been used to convert optical power to operate a valve, which depend on the actuator type.                1. Convert optical power to electrical power by using a photovoltaic device or photo diode to drive the actuator in the valve, preferably a ferroelectric actuator.        2. Convert optical power to heat energy; this technique can be used with a valve using a temperature operated actuator such as a bimetallic actuator, thermo-mechanical actuator or shape memory alloy.        3. Use the optical power to operate the actuator in the valve directly, for example a valve which uses a photosensitive material actuator.        
U.S. Pat. No. 5,709,245 discloses an optically controlled actuator employing a laser, an optical fibre and a photocell which energises coils of an electro-hydraulic valve.